Epoxy resin and adhesive composition containing the same

ABSTRACT

An adhesive composition comprising (a) an epoxy resin obtained by reacting a 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubustituted disiloxane dianhydride with an alcohol or alcohol derivative, followed by reaction with an epoxy compound having two or more epoxy groups, or an epoxy resin obtained by reacting a 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane with an epoxy compound having two or more epoxy groups and (b) a curing agent is suitable for bonding semiconductor chips to a copper frame with a small warpage of the chips.

BACKGROUND OF THE INVENTION

This invention relates to an epoxy resin, an adhesive compositioncontaining such an epoxy resin, a process for producing such an epoxyresin having good flexibility and use of the adhesive composition forproducing a semiconductor device.

As aromatic epoxy resins, there have been known bisphenol A type,bisphenol F type and bisphenol AD type epoxy resins obtained frombisphenol and epichlorohydrin, phenol novolak type epoxy resins andcresol novolak type epoxy resins obtained from novolak resins, andnaphthalene skeleton-containing or alicyclic epoxy resins. Thesearomatic epoxy resins are used together with amine curing agents, acidanhydride curing agents, phenol resin curing agents, or the like, ascasting resins, molding materials for electric and electronic parts,etc. With the development of recent technology, it is desired to have alower modulus of elasticity.

On the other hand, as epoxy resins containing siloxane linkages, therehave been known1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane,3-glycidoxypropyldimethylpolysiloxane, etc. But, it is impossible tolower the modulus of elasticity when1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane is used.Further, when 3-glycidoxypropyldimethylpolysiloxane is used, the modulusof elasticity can be lowered, but heat resistance is also lowered.

Thus, an epoxy resin which can lower the modulus of elasticity withoutlowering heat resistance is desired.

On the other hand, in the assembly of resin encapsulated semiconductordevices, solder or electroconductive adhesives have been used in orderto lower the production cost in a step of bonding IC's, LSI's, etc. tolead frames. As the electroconductive adhesives, there are generallyused compositions comprising an epoxy resin mixed with a silver (Ag)powder, a novolak type phenol resin as a curing agent for the epoxyresin (bisphenol A type or novolak type) and a curing accelerator suchas an imidazole as disclosed in Japanese Patent Examined Publication No.63-4701.

Recently, with higher density of integration of LSI's, chips areenlarged. On the other hand, lead frames of iron alloys such as 42 alloylead frames are to be substituted with copper frames. When chips arebonded to such copper frames using the above-mentioned epoxy resinadhesive, warpage of chips becomes larger with the enlargement of chips,resulting in changing properties. The warpage of chips is caused bystress generated from a difference in thermal expansion coefficients ofchips and copper (chips 3.5×10⁻⁶ l/°C, copper frame 17×10⁻⁶ l/°C, 42alloy lead frame 4.4×10⁻⁶ l/°C).

The warpage of chips also depends on a modulus of elasticity ofadhesive. The smaller the modulus of elasticity becomes, the smaller thewarpage of chips becomes due to absorption of the stress mentionedabove.

Therefore, adhesives having a low modulus of elasticity which can absorbthe stress between chips which are to be enlarged more and morehereinafter and copper frames, and rapid curing properties are demanded.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an adhesivecomposition containing an epoxy resin and relaxing the warpage of chips.It is another object of the present invention to provide epoxy resinsand processes for producing such epoxy resins used in the adhesivecomposition. It is a further object of the present invention to providea process for using the adhesive composition for producing asemiconductor device.

The present invention provides an adhesive composition comprising anepoxy resin obtained by reacting a1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane dianhydridewith an alcohol or alcohol derivative, followed by reaction with anepoxy compound having two or more epoxy groups, or an epoxy resinobtained by reacting a 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituteddisiloxane with an epoxy compound having two or more epoxy groups.

The present invention also provide a process for using the adhesivecomposition mentioned above for producing a semiconductor device.

The present invention further provides an epoxy resin represented by theformula: ##STR1## wherein R is an alkyl group or a phenyl group; R₁ is aresidue of an alcohol; R₃ is a residue of an epoxy compound; and theester groups are independently bonded to 2- and 3-positions or 3- and4-positions, or an epoxy resin represented by the formula; ##STR2##wherein R is as defined above; R₄ and R₅ are independently a residue ofan epoxy compound; and the ester groups are independently bonded to 2-and 3-positions or 3- and 4-positions.

The present invention further provides a process for producing an epoxyresin, which comprises reacting a1,3-is(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane dianhydridewith an alcohol or alcohol derivative, followed by reaction with anepoxy compound having two or more epoxy groups.

The present invention still further provides a process for producing anepoxy resin, which comprises reacting a1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane with anepoxy compound having two or more epoxy groups.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a chart of gel permeation chromatography of the reactionproduct obtained in Example 1.

FIG. 2 is a ¹ H-NMR spectrum of the reaction product obtained in Example2.

FIG. 3 is a ¹ H-NMR spectrum of R-710.

FIG. 4 is a ¹ H-NMR spectrum of SXDA.

FIG. 5 is an IR spectrum of the reaction product obtained in Example 2.

FIG. 6 is an IR spectrum of SXDA.

FIG. 7 is a ¹ H-NMR spectrum of the reaction product obtained in Example4.

FIG. 8 is an IR spectrum of the reaction product obtained in Example 4.

FIG. 9 is an IR spectrum of SXTA.

FIG. 10 is a perspective view of a lead frame coated with an adhesivecomposition.

FIG. 11 is a cross-sectional view of a semiconductor device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxanedianhydride is represented by the formula: ##STR3## wherein R is analkyl group preferably having 1 to 3 carbon atom or a phenyl group; andcarboxylic acid anhydride groups are independently bonded to 2,3-positions or 3, 4-positions.

The 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane isrepresented by the formula: ##STR4## wherein R is as defined above; andcarboxyl groups are independently bonded to 2, 3-positions or 3,4-positions.

The alcohol or alcohol derivative is represented by the formula:

    HO--R.sub.1                                                (III)

wherein R₁ is a saturated or unsaturated organic group such as an alkylgroup, a residue of alcohol and having one or more double bonds, esterlinkages or ether linkages; said organic group may contain one or moreether linkages or one or more ester linkages.

The epoxy resins produced by the processes of the present invention havethe following skeleton: ##STR5##

As the epoxy compound, there can be used the following compoundsrepresented by the formulae: ##STR6## wherein R₂ is a monovalent,divalent or trivalent organic group such as an alkyl group, an alkylether group, an alkyl ester group, an alkylene group, an alkylene ethergroup, an alkylene ester group, an aromatic group, an aromatic ethergroup, an aromatic ester group, etc.

As the epoxy compound, those having two or more epoxy groups are used.It is also possible to use two or more epoxy compounds having one epoxygroup, or to use an epoxy compound having one epoxy group together withan epoxy compound having two or more epoxy groups.

Using the above-mentioned raw materials, the epoxy resins can beproduced. For example, the epoxy resin of the formula (VIII) can beproduced by reacting the dianhydride of the formula (I) with the alcoholor alcohol derivative of the formula (III), followed by reaction withthe epoxy compound of the formula (VI) as follows: ##STR7##

Further, the epoxy resin of the formula (IX) can be produced by reactingthe siloxane of the formula (II) with the epoxy compound of the formula(V) and the epoxy compound of the formula (VI). ##STR8##

The epoxy resin represented by the formula: ##STR9## wherein R is analkyl group or a phenyl group; R₁ is a residue of an alcohol; R₃ is aresidue of an epoxy compound; and the ester groups are independentlybonded to 2- and 3-positions or 3- and 4-positions, is novel.

Further, the epoxy resin represented by the formula: ##STR10## wherein Ris an alkyl group or a phenyl group; R₄ and R₅ are independently aresidue of an epoxy compound; and the ester groups are independentlybonded to 2- and 3-positions or 3- and 4-positions, is also novel.

These epoxy resins can be produced as follows.

A 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxanedianhydride (I) is reacted with an alcohol or alcohol derivative (III)preferably in equivalent amounts, if necessary in the presence of asolvent, followed by reaction with an epoxy compound having two or moreepoxy groups, if necessary in the presence of a catalyst to produce anepoxy resin.

Further, a 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxaneis reacted with an epoxy compound having two or more epoxy groups, ifnecessary in the presence of a solvent and catalyst to produce an epoxyresin.

As the 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxanedianhydride of the formula (I), there can be used1,3-bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane dianhydride(SXDA),1-(2,3-dicarboxyphenyl)-3-(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxanedianhydride, etc.

As the 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituetd disiloxane ofthe formula (II), there can be used1,3-bis(3,4-dicarboxyphenyl-1,1,3,3-tetramethyldisiloxane (SXTA),1-(2,3-dicarboxyphenyl)-3-(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane,etc.

As the alcohol or alcohol derivative of the formula (III), there can beused monohydric alcohols such as methanol, ethanol, propanol,isopropanol, butanol, allyl alcohol, oleyl alcohol, etc.; polyhydricalcohols such as ethylene glycol, propylene glycol, glycerine,trimethylolpropane, etc.; ethoxy ethanol, butoxy ethanol, etc. Thesealcohols or alcohol derivatives can be used alone or as a mixturethereof.

As the epoxy compound having two or more epoxy groups, there can be useddivalent epoxy resins such as diglycidyl ether bisphenol A, diglycidylether bisphenol AD, diglycidyl ether bisphenol F, diglycidyl etherbisphenol S, a naphthalene skeleton-containing epoxy resin, a biphenylskeleton-containing epoxy resin, diglycidyl ether ofdihydroxybenzophenone, a spiro ring skeleton-containing epoxy resin, acyclic aliphatic diepoxide, dipentene epoxide,1,3-bis(glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane, etc.; polyvalentepoxy resins such as phenol novolak epoxy resin, cresol novolak epoxyresin, etc. These epoxy compounds can be used alone or as a mixturethereof.

As the epoxy compound having one epoxy group, there can be used butylglycidyl ether, allyl glycicyl ether, glycidyl esters of long chainfatty acids having 12 to 14 carbon atoms, propylene oxide, phenylglycidyl ether, cresyl glycidyl ether, vinylcyclohexene oxide, etc.

As the solvent which is used if necessary, there can be used aromaticsolvents such as toluene, xylene, etc.; alcohol derivatives such asethylene glycol monobutyl ether, ethylene glycol monobutyl etheracetate, etc.; ketone series solvents such as N-methyl-2-pyrrolidone,etc. These solvents can be used alone or as a mixture thereof.

As the catalyst which is used if necessary, there can be used aminecatalysts such as benzyldimethylamine, etc.; organic phosphine compoundssuch as triphenyl phosphine, etc.

The epoxy resin can be produced, for example, by addition reacting 1mole of the dianhydride of the formula (I) with 2 moles of alcohol oralcohol derivative of the formula (III) in ethylene glycol monobutylether acetate at 80° to 150° C. (esterification), followed by reactionwith about 2 moles of an epoxy compound having two epoxy groups at 60°to 120° C.

Alternatively, the epoxy resin can be produced, for example, by reacting1 mole of disiloxane of the formula (II) with 1 to 3 moles of amonovalent epoxy resin in ethylene glycol monobutyl ether acetate in thepresence of benzyldimethylamine at 80° top 150° C., followed by reactionwith 1 to 3 moles of an epoxy compound having two epoxy groups at 60° to120° C.

Such a series of reactions can be traced by measuring an acid value.

The thus obtained epoxy resins (those of the formulae (X) and (XI)) canbe used for preparing an adhesive composition, a coating composition,etc.

The adhesive composition of the present invention comprises the epoxyresin of the formula (X) obtained by reacting a1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane dianhydrideof the formula (I) with an alcohol or alcohol derivative, followed byreaction with an epoxy compound having two or more epoxy groups, or theepoxy resin of the formula (XI) obtained by reacting a1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane of theformula (II) with an epoxy compound having two or more epoxy groups.

As the curing agent, there can be used polyhydric phenols, polybasicacids, aromatic polyamines, imidazoles, etc.

The polyhydric phenols are condensates of a phenol and an aldehydeobtained in the presence of a basic catalyst. Such condensates includenovolak type phenol resins mainly having 2 or 3 nuclea obtained bycondensing a monohydric phenol such as phenol, cresol, xylenol, or thelike, or a polyhydric phenol such as resorcin, catechol, hydroquinone,or the like with formaldehyde in the presence of an acidic catalyst.

As the polybasic acids, there can be used pyromellitic anhydride,trimellitic anhydride, maleic anhydride, phthalic anhydride,endomethylenetetrahydrophthalic anhydride, hexahydrophthalic anhydride,etc.

As the aromatic polyamines, there can be used diaminodiphenylmethane andderivatives thereof, etc.

As the imidazoles, there can be used 2-phenyl-4-ethyl-5-hydroxymethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole,1-benzyl-2-methylimidazole, etc.

These curing agents can be used alone or as a mixture thereof. Amongthem, the novolak type phenol resins are preferable.

The adhesive composition may further contain one or more curingaccelerators, coupling agents, fillers, reactive diluents, solvents, andthe like.

As the curing accelerators, there can be used organic phosphinecompounds such as triphenyl phosphine, etc.; boron salts such astetraphenyl borate of 1,8-diazabicyclo(5,4,0)undecene-7, etc.;imidazoles such as 2-phenyl-4-methyl-5-hydroxymethylimidazole, etc.

As the fillers, there can be used inorganic insulating powders such as asilica powder, an alumina powder, etc.; electroconductive powders suchas a gold powder, a silver powder, a nickel powder, a graphite powder,carbon black, etc. These fillers can be used alone or as a mixturethereof. The use of a silver powder as an electroconductive powder and asilica powder as an insulating powder is preferable.

As the reactive diluents, there can be used conventionally used onessuch as phenyl glycidyl ether, cresyl glycidyl ether, etc.

As the solvents, there can be used alcohol derivatives such as butylCellosolve, butyl Cellosolve acetate, etc.; nitrogen-containing solventssuch as N-methyl-2-pyrrolidone, etc.; aromatic solvents such as xylene,toluene, etc.; ketones such as methyl ethyl ketone, methyl isobutylketone, etc.

The adhesive composition can be prepared by dissolving and mixing theepoxy resin obtained as mentioned above and a novolak phenol resin in aflask at 80° to 100° C., cooling the resulting mixture to 20° to 30° C.,and kneading a silver powder as a filler, a curing accelerator, acoupling agent, and the like using a three-roll mill.

The adhesive composition can be used for bonding semiconductor elementsto a lead frame made of, for example, copper. For example, asemiconductor device as shown in FIG. 11 can be produced by coating theadhesive composition 4 on a copper frame as shown in FIG. 10 using adispenser, mounting a semiconductor element 3, curing the adhesivecomposition in a hot air circulating oven at 150° C. to 200° C. or usinga heat block at 200° C. to 350° C., connecting the semiconductor elementto the lead frame with wires 5, and encapsulating the resulting memberwith a resin such as epoxy molding compound 6 conventionally used.

FIG. 10 is a perspective view of a lead frame on which the adhesivecomposition is coated. In FIG. 10, numeral 1 denotes a lead frame,numeral 2 denotes an island of lead frame, and numeral 4 is the adhesivecomposition.

FIG. 11 is a cross-sectional view of a semiconductor device, whereinnumeral 3 denotes a semiconductor element (IC chip), numeral 5 is awire, and numeral 6 is an epoxy molding compound.

Thus, there is provided a semiconductor device comprising a substrate (alead frame), an adhesive composition coated on an island of the leadframe, a semiconductor element placed on the adhesive composition andbonded to the island of the lead frame via the adhesive composition,wires connecting the semiconductor element and the lead frame, and amolded resin encapsulating the whole of the lead frame and thesemiconductor element.

Since the epoxy resin used in the present invention has goodflexibility, the adhesive composition containing such an epoxy resinseems to lower the modulus of elasticity after cured, resulting inmaking the warpage of chips bonded to the copper frame remarkably small.

The present invention is illustrated by way of the following Examples,in which all parts and percents are by weight unless otherwisespecified.

PRODUCTION EXAMPLE 1

1,3-Bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane dianhydride(SXDA, molecular weight 426 or less) in an amount of 27.6 parts wasreacted with 35 parts of n-octadecyl alcohol (molecular weight 270) at140° C. for 1 hour. Then, 52.9 parts of diglycidyl ether bisphenol AD(R-710, a trade name, mfd. by Mitsui Petrochemical Industries, Ltd.,molecular weight 326, epoxy equivalent 163) and 0.1 part ofbenzyldimethylamine were added to the reaction solution and reacted at80° C. for 3 hours to obtain a reaction product from SXDA and the epoxycompound. The resulting product had an acid value of 17.

FIG. 1 shows a chart of gel permeation chromatography (GPC). FIG. 1shows that the reaction product has a molecular weight of 1500 (23.69min).

PRODUCTION EXAMPLE 2

SXDA in an amount of 27.6 parts, 4.2 parts of octyl alcohol (molecularweight 130), and 26.2 parts of n-octadecyl alcohol were reacted at 120°C. for 1 hour. Then, 46.5 parts of R-710 and 1 part ofbenzyldimethylamine were added to the reaction solution and reacted at80° C. for 5 hours to obtain a reaction product from SXDA and the epoxycompound. The reaction product had an acid value of 17.

FIG. 2 shows ¹ H-NMR spectrum of the thus obtained reaction product. ¹H-NMR spectra of R-710 and SXDA are shown in FIGS. 3 and 4,respectively.

In FIG. 3, the intensity ratio of the aromatic ring H proton occurringat 6.8 to 7.2 ppm to one H proton in the CH₂ in the glycidyl ringoccurring at 2.7 ppm is 8/2 (123/31). This shows that two glycidylgroups are adducted to two aromatic rings.

When FIG. 2 is analyzed in the same manner as mentioned above, theabove-mentioned proton intensity ratio becomes 8/1 (24/3). This meansthat a half of the glycidyl groups is reduced by the reaction.

On the other hand, FIG. 4 shows ¹ H-NMR spectrum of SXDA, wherein a peakdue to the H proton in aromatic ring is shown at about 8 ppm. In FIG. 2,the ratio of the intensity (24) of the H proton in the aromatic ring ofepoxy compound at 6.8-7.2 ppm to the intensity (8) of aromatic ring ofSXDA at about 8 ppm is 24/8. This means that 2.2 moles of epoxy compoundis adducted to 1 mole of SXDA. Further, the peak at 0.4 ppm in FIG. 2 isdue to "--CH₃ " in Si--(CH₃)₃.

PRODUCTION EXAMPLE 3

Using the same formulation as used in Production Example 2, SXDA wasreacted with the alcohol at 140° C. for 1 hour, followed by reactionwith the epoxy compound at 80° C. for 5 hours to give a reaction producthaving an acid value of 6.9.

FIG. 5 shows an lR spectrum of a mixture obtained by adding 6 parts ofγ-glycidoxypropyltrimethoxysilane (KBM-403, mfd. by Shin-Etsu ChemicalCo., Ltd.) to the resulting reaction product.

FIG. 6 shows an lR spectrum of SXDA.

As is clear from FIGS. 5 and 6, the absorptions at 1750 and 1850 cm⁻¹due to aromatic acid anhydride group shown in FIG. 6 are not shown inFIG. 5 wherein the absorption at 1720 cm⁻¹ due to the carbonyl of esterand the absorption at 900 cm⁻¹ due to epoxy group are shown, instead.This means that the carboxylic acid is esterified and epoxy is retained.

PRODUCTION EXAMPLE 4

1,3-Bis(dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane (hereinafterreferred to as "SXTA", molecular weight 462) in an amount of 17.9 partsand 19.4 parts of Cardura E-10 (a trade name, mfd. by Yuka Shell EpoxyKabushiki Kaisha, molecular weight 250) were reacted at 125° C. for 6hours, followed by addition of 34.3 parts of epoxy resin YX-400 (a tradename, mfd. by Dainippon Ink and Chemicals, Inc., epoxy equivalent 177),0.09 part of benzyldimethylamine, and 20 parts of butyl Cellosolveacetate as a solvent to the reaction solution. The reaction was carriedout at 80° C. for 16 hours, to give a reaction product having an acidvalue of 9.

FIG. 7 shows a ¹ H-NMR spectrum of the reaction product. FIG. 8 shows anIR spectrum of the reaction product. FIG. 9 shows an Ir spectrum ofSXTA.

In FIG. 7, the spectrum of H proton of CH₂ in the glycidyl ring is shownat 2.7 ppm and the spectrum of CH₃ in --Si(CH₃)₃ is shown at 0.4 ppm.Further, the absorption due to the carboxylic acid at 1740 cm⁻¹ shown inFIG. 9 is not shown in FIG. 8. In FIG. 8, the absorption due to esterlinkage is shown at 1720 cm⁻¹, the absorption due to Si--O bonding at1250 cm⁻¹ and the absorption due to the epoxy group at 900 cm⁻¹.

FIGS. 7 to 9 show that the skeleton of SXTA has the epoxy group and theester linkage.

These results show that the reaction products obtained in ProductionExamples 1 to 4 are epoxy resins represented by the formula (X) or (XI).

EXAMPLE 1

1,3-Bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane (hereinafterreferred to as "SXTA") in an amount of 23.1 parts and 25 parts of a C₁₂-C₁₄ long chain aliphatic glycidyl ester (Cardura E-10, a trade name,mfd. by Shell Chemical Co.) were reacted in the presence of 0.09 part ofbenzyldimethylamine as a catalyst at 120° C. for 5 hours. Then, 35 partsof biphenyl skeleton-containing epoxy resin (YX-4000, a trade name, mfd.by Dainippon Ink & Chemicals, Inc.; an epoxy equivalent; 177) and 36parts of ethylene glycol monobutyle ether acetate as a solvent wereadded to the reaction solution and reacted at 80° C. for 8 hours toobtain an epoxy resin from SXTA and the epoxy compound.

To 143 parts of the epoxy resin, 13 parts of novolak phenol resin (H-1,a trade name, mfd. by Meiwa Plastic Industries, Ltd., weight averagemolecular weight, 800) and 20 parts of ethylene glycol monobutyl etherwere added and heated with stirring at 80° C. for 30 minutes forsolving. After cooling to 20° to 30° C., 6 parts of tetraphenylphosphonium tetraphenyl borate and 339 parts of a silver powderflake-like form, TCG-1, a trade name, mfd. by Tokuriki Chemical ResearchCo., Ltd. average particle size 2.8 μm) were added to the resultingmixture and kneaded using a three-roll mill to give a uniform adhesivecomposition.

EXAMPLE 2

1,3-Bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane dianhydride(hereinafter referred to as "SXDA") in an amount of 21.3 parts and 12parts of ethylene glycol monobutyl ether were reacted in 29 parts ofethylene glycol monobutyl ether acetate at 120° C. for 2 hours. Then, 35parts of diglycidyl ether bisphenol F (YDF-170, a trade name, mfd. byTohto Kasei Co., Ltd., epoxy equivalent 175) and 0.03 part ofbenzyldimethylamine were added to the reaction mixture and reacted at80° C. for 3 hours to give an epoxy resin which is a reaction product ofSXDA and the epoxy compound.

To 143 parts of the epoxy resin, 16 parts of novolak resin (H-1, a tradename, mfd. by Meiwa Plastic Industries, Ltd., weight average molecularweight 800) and 20 parts of ethylene glycol monobutyl ether were addedand heated with stirring at 80° C. for 30 minutes for solving. Aftercooling to 20° C. to 30° C., 3 parts of tetraphenyl borate of1,8-diazabicyclo(5,4,0)undecene-7 and 348 parts of a silver powder(flake-like form, TCG-1, a trade name, mfd. by Tokuriki ChemicalResearch Co., Ltd., average particle size 2.8 μm) were added to theresulting mixture and kneaded using a three-roll mill to give a uniformadhesive composition.

EXAMPLE 3

The process of Example 2 was repeated except for using 3 parts of asilica powder (Aerosil #380, a trade name, mfd. by Nippon Aerosil Co.,Ltd.) in place of 348 parts of the silver powder to give an adhesivecomposition.

COMPARATIVE EXAMPLE 1

An adhesive composition was prepared in the same manner as described inExample 1 except for using 10 parts of glycidyl ether bisphenol A(Epikote 1001, a trade name, mfd. by Shell Chemical Co.), 2.4 parts ofnovolak phenol resin, 13 parts of ethylene glycol monobutyl ether, 0.6part of tetraphenyl phosphonium tetraphenyl borate and 39 parts of asilver powder (TCG-1, a trade name) in place of the epoxy resin which isa reaction product of SXTA and epoxy compound obtained in Example 1.

COMPARATIVE EXAMPLE 2

An adhesive composition was prepared in the same manner as described inExample 2 except for using 10 parts of novolak type epoxy resin(DEN-438, a trade name, mfd. by Dow Chemical Co.), 15 parts of ethyleneglycol monobutyl ether, 5 parts of novolak phenol resin (H-1, a tradename), 0.3 part of tetraphenyl borate salt of undecene and 45 parts of asilver powder (TCG-1, a trade name) in place of the epoxy resin which isa reaction product of SXDA and epoxy compound obtained in Example 2.

The resulting adhesive compositions were subjected to evaluations ofvarious properties.

The results are shown in Table 1.

                  TABLE 1                                                         ______________________________________                                                                 Warpage of                                                  Adhesive strength*.sup.1                                                                        chips*.sup.2                                                  Cured at    Cured at    (cured at                                             180° C./1 hr                                                                       150° C./60 sec                                                                     180° C./1 hr)                         Example No.                                                                            (kg/chip)   (kg/chip)   (μm)                                      ______________________________________                                        Example 1                                                                              5 or more   3.3         24                                           Example 2                                                                              5 or more   3.5         20                                           Example 3                                                                              5 or more   3.5         10                                           Comparative                                                                            5 or more   1.5         60 or more                                   Example 1                                                                     Comparative                                                                            5 or more   2.8         60 or more                                   Example 2                                                                     ______________________________________                                         Note)                                                                         *.sup.1 A silver plated copper frame was coated with an adhesive              composition and bonded to a Si chip with 2 mm□ at a temperatur     for a period listed in Table 1, followed by measurement of adhesive           strength (shear force) at room temperature (23° C.) using a            pushpull gauge.                                                               *.sup.2 A silver plated copper frame was coated with an adhesive              composition and bonded to a silicon chip of 5 mm × 13 mm with           heating at 180° C. for 1 hour. The warpage of the chip in the          distance of 11 mm among 13 mm was measured using a surface roughness          meter.                                                                   

As mentioned above, since the epoxy resins obtained by the processes ofthe present invention have good flexibility, the adhesive compositioncontaining such epoxy resins provides a low modulus of elasticity aftercured. When the adhesive composition is used in a semiconductor device,the warpage of IC and LSI chips is small and high reliability isobtained against heating cycles.

What is claimed is:
 1. An adhesive composition comprising an epoxy resinobtained by reacting a 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituteddisiloxane dianhydride with an alcohol, followed by reaction with anepoxy compound having two or more epoxy groups, or an epoxy resinobtained by reacting a 1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituteddisiloxane with an epoxy compound having two or more epoxy groups.
 2. Anadhesive composition according to claim 1, wherein an epoxy compoundhaving one epoxy group and the epoxy compound having two or more epoxygroups are reacted with the1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane.
 3. Anadhesive composition according to claim 1, which further comprises as acuring agent a novolak phenol resin.
 4. An adhesive compositionaccording to claim 1, which further comprises a filler.
 5. An adhesivecomposition according to claim 4, wherein the filler is anelectroconductive powder.
 6. An adhesive composition according to claim5, wherein the electroconductive powder is a silver powder.
 7. Anadhesive composition according to claim 4, wherein the filler is aninorganic insulating powder.
 8. A process for producing an epoxy resin,which comprises reacting a1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane dianhydridewith an alcohol, followed by reaction with an epoxy compound having twoor more epoxy groups.
 9. A process according to claim 8, wherein anepoxy compound having one epoxy group and the epoxy compound having twoor more epoxy groups are reacted with the1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxanedianhydride-alcohol reaction product.
 10. A process for producing anepoxy resin, which comprises reacting a1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane with anepoxy compound having two or more epoxy groups.
 11. A process accordingto claim 10, wherein an epoxy compound having one epoxy group and theepoxy compound having two or more epoxy groups are reacted with the1,3-bis(dicarboxyphenyl)-1,1,3,3-tetrasubstituted disiloxane.
 12. Anepoxy resin represented by the formula: ##STR11## wherein R is an alkylgroup or a phenyl group; R₁ is an organic residue of an alcohol obtainedby removal of a hydroxyl group from the alcohol; R₃ is an organicresidue of an epoxy compound obtained by removal of an epoxy group fromthe epoxy compound, said epoxy compound being an epoxy compound havingtwo or more epoxy groups or a mixture of an epoxy compound having two ormore epoxy groups and an epoxy compound having one epoxy group; andester groups are independently bonded to 2- and 3-positions or 3- and4-positions.
 13. An epoxy resin represented by the formula: ##STR12##wherein R is an alkyl group or a phenyl group; R₄ and R₅ areindependently an organic residue of an epoxy compound obtained byremoval of an epoxy group from the epoxy compound, said epoxy compoundbeing an epoxy compound having two or more epoxy groups or a mixture ofan epoxy compound having two or more epoxy groups and an epoxy compoundhaving one epoxy group; and ester groups are independently bonded to 2-and 3-positions or 3- and 4-positions.